The Student Room Group

does the ketogenic diet work?

i'm a bit skeptical about how a diet with such a high fat content can actually result in weight loss, but is there anyone on it here with successful results?
Reply 1
The amount of fat you eat has no difference for the amount on you body. You loose weight by eating less calories than you burn, you could really do it eating nothing but peanut butter if you really wanted to.

That said, you won't be able to do that long term so it's easier to make sustainable diet changes so you can keep the weight off easier. Carbs are an essential thing your body needs, though eating less will cause you to loose water weight quite easily which helps these diets look good in the short term but that's not real weight loose. And it tends to result in cutting down fruit and veg which pretty much nobody should be doing.
Yes it works, the same way that a carb based diet works; by creating a caloric deficit. There is no fat loss advantage of a ketogenic diet over a carb based diet of the same caloric deficit but some people find them more satiating which helps when in a deficit, people also get confused and think they're a miracle diet because they drop a ****load of bloat/water at the beginning and think they're losing fat faster.
(edited 9 years ago)
Reply 3
Actually, my partner has been keto for over a year now and the reason that you lose weight on high fat is because your body doesn't need to store the energy gained from carbs anymore and can simply go after the fat you have stored on you already which is more accessible. You run on one of the two - fat or carbs - taking carbs out of the equation means you're going to burn your existing fat when your body needs energy instead of you needing to go and eat. There's lots of proven science behind it, and it does work, but it needs done properly. It is actually sustainable in the long term as well, carbs aren't an essential thing that you really really need or I'd know a lot of people in a sticky situation!

His grandmother has been doing it very successfully as well, along with a pretty decent number of friends. If you get properly into it you can still have a lot of treats too, just need to make them yourself. The initial loss is water weight true, but it does seem to have quicker results, and it can feel pretty rubbish at first as you adjust to not taking in sugars to run on anymore, but it seems worth it. I just don't adapt well and don't have time to do it or I would!
Original post by Sephits
Actually, my partner has been keto for over a year now and the reason that you lose weight on high fat is because your body doesn't need to store the energy gained from carbs anymore and can simply go after the fat you have stored on you already which is more accessible. You run on one of the two - fat or carbs - taking carbs out of the equation means you're going to burn your existing fat when your body needs energy instead of you needing to go and eat. There's lots of proven science behind it, and it does work, but it needs done properly. It is actually sustainable in the long term as well, carbs aren't an essential thing that you really really need or I'd know a lot of people in a sticky situation!


Ketogenic diets are very poorly understood by the general public.

The majority of the weight loss on low carb and Ketogenic diets is determined by calorie deficit (ie; by cutting out carbs you consume fewer calories in general, thus lose weight) and water weight (ie; carbohydrates are closely associated to water in the body).

Sure in the first couple of weeks of a ketogenic diet your body is less efficient at processing fat and protein for energy which aids weight loss slightly, but your body rapidly becomes more efficient at this process and after those first couple of weeks it is pretty much solely calorie deficit that determines weight loss.

If your boyfriend, grandmother and friends compensated for the lack of carbs in their diet by eating the amount of calories they cut as additional fat in the diet they would lose little (if any) weight, in fact they might even gain some (ie; fat is more efficiently converted to body fat than carbohydrates, around 99% vs 85-90%).

You can get the same results with a conventional healthy diet with moderate intake of carbs. Why do people struggle with this?

Why? Because it is easier to tell a fat person to cut out a type of food or nutrient that makes up a significant portion of their diet, and in doing so trigger weight loss, compared to getting that person to eat healthily, measure out portion sizes properly and match their calorific intake to their activity level.
Reply 5
None of them are in caloric deficit, and they are losing weight well past the first few weeks (months at this point) with the exception of my partner who after a year lost a lot of his remaining fat (after starting out a healthy weight according to his BMI) and is heading in to the gym to build muscle and consequently is gaining. I've sat and listened to enough science and lectures to have a reasonable understanding of how it all works.

Eating healthily is a very subjective thing to say. Each person's body will tolerate things differently. My partner has IBS and some pretty serious skin issues when he takes in carbs which disappear entirely when he cuts them out. An arthritic friend sees her inflammation and pain reduce. A diabetic has less issues with controlling her condition. The diet was originally intended to help people with epilepsy and there are people out there who find that it does. I know people who've been doing this for quite literally years and they haven't suffered for it in the slightest. It's not automatically suitable for everyone, but the question was whether anyone's had successful results and that's definitely true, but it needs to be done properly and there's a lot of resources out there for people to read.
Original post by Sephits
None of them are in caloric deficit, and they are losing weight well past the first few weeks (months at this point) with the exception of my partner who after a year lost a lot of his remaining fat (after starting out a healthy weight according to his BMI) and is heading in to the gym to build muscle and consequently is gaining.


I would be very sceptical of that unless they've been lucky enough to get onto a long term diet study or they're under close supervision of a dietician and religiously measure portion sizes and monitor their activity level.

The vast majority of people on ketogenic diets vastly cut their calorific intake (the average is around 30%) and do not add in anywhere near enough extra fat and protein to offset that. Equally a lot of people who claim to be on a ketogenic diet are not actually doing so, rather a low carb diet (again, read calorie deficit), nor do they test their urine for ketone bodies on a regular basis to confirm it either (which further undermines their claims that ketogenesis is the leading cause of their weight loss!).

As far as your boyfriend goes he also has the added advantage of the novice training effect which is enhanced in people that are overweight.

I am not belittling their accomplishments, they have all done bloody well, but you have been misled regarding the aetiology.

I've sat and listened to enough science and lectures to have a reasonable understanding of how it all works.


Like I said, the majority of mainstream "science" regarding ketogenic diets is very misleading.

Kudos if you have studied biochemistry and physiology at university, and have read what Lyle MacDonald, Shelby Starnes, John Berardi or Alan Aaragon have to say on the issue (then again if you had you probably wouldn't have said what you have already).

Eating healthily is a very subjective thing to say.


It really isn't, the advice has been pretty consistent for the last several decades:

1) Eat plenty of fruit and vegetables

2) Eat plenty of lean meats and fish

3) Dairy products, grains and starchy carbs in moderation

4) Avoid processed foods and drinks (ie; soft drinks, alcohol, takeaways, ready meals, cakes/biscuits/pastries, sweets, etc)

5) Healthy fats in moderation

6) Supplement with plenty of exercise

The water has become muddied by "bad science" in the media, "celebrity trainers", fad diets and people's desire for a quick or easy solution (for which there aren't any).

Each person's body will tolerate things differently. My partner has IBS and some pretty serious skin issues when he takes in carbs which disappear entirely when he cuts them out. An arthritic friend sees her inflammation and pain reduce. A diabetic has less issues with controlling her condition.


Carbs themselves are not the issue here, rather dietary allergies/intolerances to certain foods (eg; wheat, gluten, dairy, lactose, egg, etc) and type of carb, carbohydrate load and diet consistency with regards to your diabetic friend.

None of the above are reasons to avoid all carbs, especially in the case of your diabetic friend which could be deadly.

The diet was originally intended to help people with epilepsy and there are people out there who find that it does.


I am well aware of the use of ketogenic diets in people with epilepsy and autism however that has no bearing on whether you should or shouldn't adopt them.

I would also add that certainly in the case of epilepsy and autism the results were not a universal success. A large proportion of those that have tried it still require long term medication. I personally have yet to have a case where I have seen any discernible effect or been able to reduce my patient's medication.
Agreed with Ch0c0h01ic

Autism and epilepsy ketogenic diets were shown to be of no significant use a long time ago
Original post by Angry cucumber
Agreed with Ch0c0h01ic

Autism and epilepsy ketogenic diets were shown to be of no significant use a long time ago


Ditto Gluten Free diets, Palm Oil, Raw Diets, etc - I've had several people try them but I've had to maintain the same level of medication throughout.
Original post by ch0c0h01ic
Ditto Gluten Free diets, Palm Oil, Raw Diets, etc - I've had several people try them but I've had to maintain the same level of medication throughout.


You've had several people try them? As in people you know or patients?

I swear you're like me in that your patients are animals.....!

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